Zhuge: Toward Consistent Low Latency With Minimal Control Loop Delay

This paper demonstrates hosting IoT gadgets on the wireless AP(Access Point) at home. For this, the process and profile of the IoT gadgets need to be virtualized into JavaScript-based objects. Then, to execute and control the instances of the virtualized IoT objects on the wireless AP, a novel instance management method is required. The demonstration shows the IoT gadget registration, monitoring, and control on the wireless AP. In addition, generating mash-up instances by connecting multiple gadgets and controlling them together is performed.

Teaching wireless networking fundamentals is often difficult because many students appear to find the subject technical, and dry when presented in traditional lecture format. To overcome this problem, we provide an opportunity for experiential learning where students can learn wireless networking fundamentals by hands-on practical activities using low-cost Wi-Fi (wireless fidelity) devices such as wireless cards and access points. Students can easily set up and configure networks using wireless cards and access points more effectively. By measuring network performance such as throughput and end-to-end delays, students are able to gain a deeper understanding of wireless networking. The effectiveness of Wi-Fi-based practical activities has been evaluated by students and the teaching team. This chapter reports on the overall effectiveness of teaching and learning of wireless network using radially available low-cost Wi-Fi cards and access points.

Software Defined Networking has been adopted to improve data center network efficiency. In SDN, the controllers are responsible for exchanging information with the switches to perform specific operations such as data forwarding. The transmission of control traffic usually uses networks different from data networks. However, building an additional wired network for the control traffic leads to high cabling complexity. Since a wireless network involves almost no cabling and is easy to install, we propose a wireless solution where switches make a wireless connection with controllers via wireless access points (AP). In this design, switches are divided into clusters, and an AP is placed at the center of each cluster. An important issue is to determine the minimum number of APs such that a given control traffic demand can be met. We propose an analytical model to evaluate the system throughput for possible clusterings, and an efficient algorithm to search for the optimal one. The extensive simulations demonstrate that our method can reduce cabling complexity significantly.

We explore the use of clock skew of a wireless local area network access point (AP) as its fingerprint to detect unauthorized APs quickly and accurately. The main goal behind using clock skews is to overcome one of the major limitations of existing solutions - the inability to effectively detect Medium Access Control (MAC) address spoofing. We calculate the clock skew of an AP from the IEEE 802.11 Time Synchronization Function (TSF) time stamps sent out in the beacon/probe response frames. We use two different methods for this purpose - one based on linear programming and the other based on least-square fit. We supplement these methods with a heuristic for differentiating original packets from those sent by the fake APs. We collect TSF time stamp data from several APs in three different residential settings. Using our measurement data as well as data obtained from a large conference setting, we find that clock skews remain consistent over time for the same AP but vary significantly across APs. Furthermore, we improve the resolution of received time stamp of the frames and show that with this enhancement, our methodology can find clock skews very quickly, using 50-100 packets in most of the cases. We also discuss and quantify the impact of various external factors including temperature variation, virtualization, clock source selection, and NTP synchronization on clock skews. Our results indicate that the use of clock skews appears to be an efficient and robust method for detecting fake APs in wireless local area networks.

There has been a recent proliferation in wireless infrastructure network deployments. In a typical deployment, an installer uses either a one-time site survey or rules of thumb to place wireless access points and allocate them with channels and power levels. Because the access point location problem is inherently complex and one that requires tradeoffs among competing requirements, these approaches can result in either dead spots or significant unintended interference among wireless access points. This degrades network performance for end clients, with throughput reduction factors of 4x found in field measurements. In this paper, we take a first step towards improving client performance by coordinating choices of channels and power levels at wireless access points using a successive refinement approach. Our contributions are two-fold: first, we develop a mathematical model that crisply defines the solution space and identifies the characteristics of an optimal channel and power-level configuration. Second, we present heuristics that, under some simplifying assumptions, yield near-optimal configurations. We use Monte Carlo simulations to evaluate the performance of our heuristics. We find that the choice of heuristics for transmit power control impacts performance more than the channel allocation strategy, especially at high densities. Also, surprisingly, randomly assigning channels to access points appears to be an effective strategy at higher deployment densities. Taken together, we believe that this study paves the way to designing rapidly deployable real-world infrastructure networks that also have good performance

Real-time multimedia communication applications demand performance requirements which differ significantly from conventional data communication applications. Current local area networks (LANs) provide efficient transport for bursty data traffic; however, they cannot necessarily provide quality of service guarantees for real-time communications. In this work we introduce and investigate an experimental priority protocol for supporting real-time communication on Ethernet, a popular implementation of multiple-access broadcast bus LANs. We examine the new protocol, known as Priority Mode-CSMA/CD (PM-CSMA/CD), providing a high priority (HP) class with CSMA/CD employed for standard priority (SP) traffic. PM-CSMA/CD performance is examined through computer simulation of videotelephony workstations operating over the shared bus LAN. Over all observed traffic conditions, the priority protocol provides performance satisfying real-time packet transport requirements of audio and video streams. The primary advantage of our protocol over similar priority schemes is its physical layer compatibility with standard CSMA/CD. The protocol also provides improved channel utilization with increasing high priority load, with no penalty in SP class performance at low to medium network loads.

As wireless networks play an increasingly important role in campus communications, identifying anomalous APs(wireless access points) is becoming increasingly important. This paper proposes an unsupervised AP anomaly detection method at multiple time granularities, which does not depend on the labeling quality of training samples. In addition, the proposed method considers the APs' behavior under different time granularities and can eliminate the influence of improper selection of the time granularity on anomaly detection. Experimental results show that the proposed method can detect anomalous APs and help network administrators locate wireless network problems.

Urban residential areas are becoming increasingly dense with more and more wireless home networks being deployed in close proximity. Considering that in such a dense urban residential area, each unit has its own wireless access point (AP), deployed without any coordination with other such units, then a need arises for reducing interference and increasing overall Quality of Experience (QoE) of the clients involved. To do this, we propose that neighbouring APs — i.e., APs that are physically close to each other — form groups, where one member of the group serves the terminals of all group members in addition to its own terminals, while the other APs of the group can be silent or even turned off. The fact that participating units are deployed without any coordination makes the overall QoE vulnerable to the selfish behaviour of each unit. We propose a cooperative-neighbourhood graphical game model comprising of a network of selfishly-oriented nodes represented by a graph where the outgoing links of a certain node capture the improvement in utility that a neighbour's client may experience from a potential cooperation. We show and prove that using the proposed model provides motivation for APs to enter and remain in cooperative neighbourhoods, in which interference is decreased due to the voluntary cooperation of the neighbours.

With the fast-growing demand for mobile services, where to place the access points (APs) for providing uniformly and appropriately distributed signals in a wireless local area network (WLAN) becomes an important issue in the wireless network planning. Basically, AP placement will affect the coverage and strength of signals in a WLAN. The number and locations of APs in a WLAN are often decided on the basis of the trial-and-error method. Based on this method, the network planner first selects suitable locations to place APs through observation, and then keeps changing the locations to improve the signal strength based on the received signal. Such process is complicated, laborious and time-consuming. To overcome this problem, we investigate the back-propagation neural network (BPNN) algorithm to improve over the traditional trial-and-error method. Without increasing the number of APs, our approach only needs to adjust AP locations to overcome weak signal problems and thus increase the signal coverage for the Internet connection anywhere within the area. In our experiment, we established a WLAN on a C campus. Our experiments also indicate that placing APs according to the BPNN provided better signal coverage and met the students’ demands for connecting to the Internet from anywhere in the classroom.

Mobile edge computing (MEC) is an innovative computing paradigm to enhance the computing capacity of mobile devices (MDs) by offloading computation‐intensive tasks to MEC servers. With the widespread deployment of wireless local area networks, each MD can offload computation task to server via multiple wireless access points (WAPs). However, computation offloading can bring a higher system cost if all users select the same access points to offload their tasks. This study proposes a computation offloading strategy and resource allocation optimisation scheme in a multiple wireless access points network with MEC, which aims to minimise the system cost by providing the optimal computation offloading strategy, transmission power allocation, bandwidth assignment, and computation resource scheduling. The proposed scheme decouples the optimisation problem into subproblems of offloading strategy and resource allocation since the problem is NP‐hard. The offloading strategy involves the optimal access point selection, which is analysed by the potential game. The resource allocation is obtained using Lagrange multiplier. The authors' analysis and simulation results verify the convergence performance of the proposed scheme, and the proposed scheme outperforms the simple resource allocation scheme and the offloading strategy optimisation scheme in terms of the system cost.

The development of internet technology currently has a significant impact on education, so that it can support the learning process in a school. As one of the public schools in Malang district, SD Negeri 01 Jambearjo has utilized the internet network to support the learning process at school. However, the use of the internet network at SD Negeri 01 Jambearjo is currently still not optimized. This study discusses the comparative analysis of the performance of Mikrotik-based Wireless Access Point (WAP) and Virtual Access Point (VAP) at SD Negeri 01 Jambearjo. This research was conducted to find out which system is better to use in SD Negeri 01 Jambearjo. The WAP and VAP network systems are used by Mikrotik RB941-2nD to configure or control access points centrally. In the WAP network, an access point is used that is connected to the Mikrotik using a LAN cable, while the VAP network uses the CAPsMAN mode which combines two Mikrotik RB941-2nD with a LAN cable. The testing process uses parameters based on Quality of Service, including throughput, packet loss, delay, and jitter. In the Quality of Service test, the Wireshark application is used. The test results on the WAP network obtained an average throughput value of 3034 kbps, with packet loss of 3.16%, delay of 2.840 ms, and jitter of 0 ms. While on the VAP network, the average throughput value is 1479 kbps, with packet loss of 9.9%, delay of 4.945 ms, and jitter of 0.0011 ms. Based on the test results, the analysis results show that the WAP network has better quality than the VAP network for use in SD Negeri 01 Jambearjo.

Wireless fidelity (WiFi) networks are deployed in several varied environments all around the World. Usually, the wireless fidelity access points are always on in houses and other small companies. In buildings of large companies and public organizations and in university campuses the number of access points is elevated; they are powered using power over the ethernet and are always on. Consequently, they consume a considerable amount of electric energy. The last versions of the International Electric and Electronic Engineers 802.11 standardized procedures to save energy in a wireless fidelity terminal but not in the access point. We designed a formal method to show when energy can be saved in wireless fidelity access points considering different power supplies for the access point: an electric energy battery and a standard voltage supply. We use an external battery that stores electric energy during an interval of time from a standard voltage supply (Charge period). After that interval (Discharge period), the energy supply for the access point is the external battery. Those intervals of time are repeated sequentially (Charge and Discharge cycles). We verified our formal model implementing a hardware circuit that controls the power supply for the access point. The amount of energy saving for a large number of of access points during a long period of time is considerably high.

In this paper, we introduce the scheme for bandwidth allocation and congestion avoidance in wireless intelligent ATM networks which is based on reinforcement learning (RL). Our solution guarantees a desired bandwidth to connections which require a fixed wide bandwidth according to QoS constraints. Any unused bandwidth is momentarily backed up (returned) to Virtual Circuits. Proposed RL method is also suitable for supporting the mapping between a single ATM switch port and a wireless access points. It can control the access points in wireless intelligent ATM networks.

This study aimed to increase the range of the wireless IEEE 802.11 b/g by adding the antenna gain, testing the performance of access point with router access point mode of the wireless IEEE 802.11 b/g, and comparing the performance of access point with router access point mode of the wireless IEEE 802.11 b/g.This research was conducted in Makassar. The method used was by performing direct performance measurement of end to end node, namely: delay time, throughput and Packet Loss. Wireless access point was placed on the SPN tower (Sekolah Tinggi Kepolisian Negara/College of Police of State) of Batua. Wireless clients were placed at 2.7 km, 5.36 km, 8.81 km and 10.82 km.The results showed that wireless IEEE 802.11 b/g can be used for data communications up to 10.82 km by adding 24 dB of antenna gain. Wireless with access point mode and router access point mode experienced 100% of packet loss with 60000 bytes of window size packets’ delivery and can handle only 1000 bytes of window size packets. The performance of wireless with access point mode was better than wireless with access point router mode, as follows: For access point packet: 0% of lost wireless, 8 ms of delay time, and 1 Mbps of throughput; On the other hand, for router access point packet: 30% of lost wireless, 26 ms of delay time, and 0.31 Mbps of throughput. Wireless 802.11 B/G can be used as data communication decive for cost-effective data acquisition and has not impact to carbon emission

SummaryIn order to suppress the interference in local area networks, this paper presents a Wireless Local Area Networks (WLAN) interference self‐optimization method based on a Self‐Organizing Feature Map (SOM) neural network model. This method trains the model by using original data sets as the initial vector set and using the whole Signal to Interference plus Noise Ratio (SINR) vector generated by the change of one Wireless Access Point (AP) channel as the basic feature. After the training, the SOM neural network can quickly locate the fault AP and optimize the network according to the changes of the network environment. Simulation results reveal that the proposed scheme can efficiently locate the AP where interference happens and optimize the interference with an improved user experience. Copyright © 2016 John Wiley & Sons, Ltd.